Cornwall goes retro with heat pumps

In 2006 Carrick Housing began an ongoing programme to install ground source heating in rural properties that cannot get gas heating. Since then 311 properties in Cornwall have been retrofitted and seven council properties built with ground source heat pumps.


Carrick Housing is the arm's length management organisation (ALMO) that manages Cornwall's council stock. Carrick proposed, planned and led on the project to fit ground source heat pumps.


Carrick estimate that it costs on average £10,000 gross to retrofit a property with ground source heat pumps.

Carrick have had grant funding of up to £3,500 a property. This has come from:

  • PowerGen
  • EDF
  • Aeon
  • Earth Energy
  • Kensa Engineering.


Councillor Julian German, a Cabinet Member who represents Roseland where some of the retrofit has taken place, explains:

"Retrofit is possibly the area we can make the biggest impact for our residents and in relation to climate change. Retrofit will help to make the cost of living affordable and provide our residents with warm and comfortable homes. Retrofit is also an important driver for the economy and we are proud in Cornwall to have excellent ground source heat pump businesses."

Carrick Housing also wanted to improve the ‘Standard Assessment Procedure' (SAP) ratings of their properties. Installing ground source heat pumps and insulation into a typical three bedroom property has raised the SAP values from less than 70 to nearly 90.

Many of the rural properties in Cornwall do not have a gas supply. These houses were running oil-fired heating systems. Some were relying on open fires for warmth. The high cost of oil, gas and electric central heating was a major concern - those systems were unpopular with tenants especially when the price of oil began to rise in 2008. Many tenants were saying they could not afford to heat their homes.


There has been no opposition to the programme. Carrick consulted with tenants through the District Forum of Tenants before embarking on the programme and continues to consult with them throughout.

Ground source heat pumps have not been imposed on tenants. Carrick writes to tenants offering them the pumps. Staff then go and visit the homes of those who are interested to explain the offer to them. Most of those people have taken up the system.

However, some tenants complained that the heating was not working properly and their bills were quite high. On investigation Carrick found that those people were not using it efficiently. Some people still used immersion heaters on occasion to give the hot water a boost. The price of electricity had also gone up, which impacted residents' fuel bills.

Staff visited the properties of dissatisfied tenants to show them how to use the system efficiently.

Key learnings

  • Make sure tenants are given the proper information at the outset. When you are trying to persuade tenants to have this system, make sure you are armed with all the key facts about savings that can be made.
  • When you leave the property after installation, make sure you have properly shown each tenant how to use the system efficiently. And then get them to show you. If you do that, you will get more take-up and the tenant will get more out of their heating system.
  • Provide easy-to-use guides on how the system is used to help tenants use the system correctly. Pictures help.
  • Warn tenants on what to expect from the drilling required for installation, as this can be quite disruptive.
  • Install the system programmer somewhere light and at eye height so that tenants can see it easily.


One tenant, from Pendower Road in Veryan, says:

"Very happy with our heating. Sufficient heat and lower cost. No problems. Thank you. No worries of oil running out like before."

70 per cent of tenants are happy with the system. Of these, 92 per cent of tenants in flats and bungalows and 55 per cent of those in houses were satisfied. These figures come from the Carrick District Forum of Tenants' ‘Tenant Inspection Report 2009-2010', which says:

"Ground source heating in bungalows and flats has an excellent satisfaction rate, and most tenants in houses are also satisfied. The hot water provision is very satisfactory and we recommend installing ground source heating under-floor in properties newly built."

Ground source heat pumps are also cheaper to maintain. The pressurised pump needs an annual safety check, which costs about £40-£50 a year. But it does not need servicing like a gas boiler, which costs about £140.

Ian Smith, Director of Cornwall Sustainable Energy Partnership, says:

"Carrick Housing has made a major contribution in helping to beat fuel poverty in Cornwall by providing affordable heating to many rural households. This solution is reducing the use of carbon fuel and has also helped Cornwall meet our CO2 reduction goal."


Pete Jarman, Operations Director
Carrick Housing
Telephone: 01872 224658